Non-kin carers provide vital resources for older people living alone with increasing care needs, especially if they cannot rely on the support of family members. However, this kind of commitment presents numerous challenges throughout the care trajectory and beyond. To explore these aspects in more depth, a qualitative study was designed including a retrospective interpretation of interview data with non-kin carers (n = 15) and additional in-depth interviews (n = 8) with people who had cared for an older person living alone with no family nearby. Analyses of the verbatim transcriptions followed coding procedures and were supported by MaxQDA software. Our findings demonstrate that non-kin carers had to negotiate personal boundaries continuously over the end-of-life trajectory to deal with the increasing complexity of care demands and overburdening situations. Following the older person's death, non-kin carers were involved in funeral arrangements and settled practical or legal matters when no family members were available or had little inclination to contribute. The findings highlight that non-kin carers make a great effort to safeguard the interests and needs of older people living alone, ensuring their autonomy and dignity towards the end of life and beyond. However, the burdens experienced require future research to better understand the support needs of non-kin carers providing end-of-life-care for an older person living alone.